"We have this really great tool to improve our partnership," she told her colleagues at the conference. "This is an incredible space and an incredible opportunity."

For doctors who couldn't imagine "friending" a patient or worry that the personal-professional boundary could blur to the point it could cause angst on either side, Dr. Jennifer Kesselheim, co-chair of the ethics advisory committee at Dana-Farber Cancer Institute in Boston, offered a few examples.

In one case, a young doctor bonded with the parents of a child with leukemia. Just before the child was to leave the hospital, the mother asked to "friend" the doctor, who agreed, expecting to see the family again and not wanting to insult them.

A few days later, he saw postings from the mother, including pictures from a bar, drinking to celebrate her child's hospital discharge.

Too much information might well change the doctor's relationship with the family, Kesselheim noted.

Doctors and medical students, too, have pushed online boundaries.

For medical students who have grown up with Facebook and Twitter, social media may be difficult to do without when they begin their professional lives.

A majority of medical schools surveyed report unprofessional online conduct by students, Kesselheim noted, but most do not have a social media policy.

A recent survey found that 90 percent of state medical boards reported at least one online professional standards violation by a doctor. In Rhode Island, an emergency room doctor was fired for a Facebook post about an unnamed patient.

In some ways, social media present situations not unlike those in a small town, where doctors and patients might meet at church or in the grocery store, and doctors have to decide where the boundaries are. Chat at the church social? Attend a patient's funeral? Go to the family's house for lunch?

Probably no medical groups have had more experience with virtual visits with patients than Group Health Cooperative and Kaiser Permanente, which began secure patient-provider emailing nearly a decade ago.

"Our doctors email patients at home, on vacation, at work; we've gotten very comfortable with it," says Dr. Ted Eytan, formerly of Group Health and now heading Kaiser's 17,000-physician group. "It's been a huge change. It encourages physicians and nurses to think about patients in their whole life, not just medical care."

Dr. Matt Handley, a family doctor and medical director for quality and informatics at Group Health, says it's not difficult to draw a line.

"I've gone skiing or cycling with patients who are friends," says Handley, who does "friend" some patients on Facebook.

In both cases, it's only with people he's actually friends with. And like those who counsel "elevator rules," he never, ever talks about work on his Facebook page, he says.

To be a good doctor takes conversation, Handley says, and at the heart of conversation is a relationship. "The more you understand and know about a patient, the more you can understand what matters for them," he says.

Surveys show patients, though influenced by celebrities, overwhelmingly trust their doctors for medical information.

And some want to know them as people too.

Years ago, Swanson said, she believed it was unprofessional to answer that frequent question patients ask: "Doctor, what would you do?"

Then she saw actress Jenny McCarthy on "Oprah" espousing a vaccine/autism link, a theory widely discredited by mainstream medicine. She realized how powerful personal stories are for patients and now responds.

"They say, 'Dr. Swanson, did your son get his MMR shot on time?'

"I say 'Yep.' And they say, 'OK, we'll do it.'"

Dr. Jen Dyer was practicing as an endocrinologist in Ohio. Infrequent office visits, she found, weren't enough to motivate her young diabetic patients to get a grip on their blood sugar levels.

But texting? OMG! Another story entirely. With a young medical student, Dyer, now a full-time tech entrepreneur, developed an app to automate weekly texts to patients.

She picked up a "cheeky, fun" name given her by a patient — the "Endogoddess" — as her Twitter handle and began tweeting out tips, from links to medical articles on current topics to advice for handling insulin during a hot afternoon baseball game.